Lexus SC300 / Lexus SC400. Manual - part 15

RECOVERING OF REFRIGERANT IN
REFRIGERANT SYSTEM

When discharging refrigerant from the system as follows, use
a recovery machine to recover the refrigerant.

Before replacing parts on the refrigerant line.
When moisture or air gets in the refrigerant line.
When excess refrigerant is charged.

NOTICE:

•

When handling the recovery machine, always follow
the directions given in instruction manual.

•

After recovery, the amount of compressor oil
removed must be measured and same amount
added into the system.

1. 

INSTALL MANIFOLD GAUGE SET TO SERVICE VALVES
See page 

AC–15

2. RECOVER 

REFRIGERANT 

FROM 

REFRIGERATION

SYSTEM
(a)  Connect the center hose to recovery machine.

(b)  Operate the recovery machine.
(c)  Open both high and low hand valves of manifold gauge

set.

3. 

STOP RECOVERY MACHINE WHEN RECOVERING HAS
FINISHED

4.  REMOVE MANIFOLD GAUGE SET FROM SERVICE

VALVES
See page 

AC–15

AC–16

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AIR CONDITIONING SYSTEM

Recovering of Refrigerant in Refrigerant System

EVACUATING AIR IN
REFRIGERATION SYSTEM AND
CHARGING WITH REFRIGERANT

HINT: Before charging the system with refrigerant, be sure
carry out a complete evacuation of the system.

1. 

INSTALL MANIFOLD GAUGE SET TO SERVICE VALVES
See page 

AC–15

2. 

EVACUATE AIR IN REFRIGERATION SYSTEM
(a)  Connect the center hose of the manifold gauge set to

the vacuum pump.

(b)  Open both the high and low hand valves and run the

vacuum pump.

HINT: If opening the low pressure hand valve pulls the high
pressure gauge into the vacuum range, there is no blokage
in the system.
(c)  After ten minutes or more, check that the low pressure

gauge indicates 99.99 kPa (750 mmHg, 29.53 in.Hg) or
more of vacuum.

HINT: If the reading is not 99.99 kPa (750 mmHg, 29.53
in.Hg) or more of vacuum, close both the high and low hand
valves of the manifold gauge set and stop vaccum pump.
Then, check the system for leaks and repair as necessary.
(d)  Close both the high and low hand valves and stop the

vacuum pump.

(e)  Leave the system in this condition for five minutes or

longer and check that there is no change in the gauge
indicator.

3. 

INSTALL CHARGING CYLINDER
NOTICE: When handling the charging cylinder, always
follow the directions given in the instruction manual.
(a)  Charge the proper amount of refrigerant in charging

cylinder.

(b)  Connect the center hose to charging cylinder.
NOTICE: Do not open both high and low hand valves of
manifold guage set.
(c)  Press on the schrader valve on the side of manifold

gauge and expel the air inside of the center hose.

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AIR CONDITIONING SYSTEM

Evacuation Air in Refrigeration 
System and Charging with Refrigerant

AC–17

4. 

INSPECT REFRIGERATION SYSTEM FOR LEAKS
HINT: After evacuating the air in system, check the system for
leakage.
(a)  Open the high pressure hand valve to charge the

system with refrigerant.

(b) When 

the 

low 

pressure 

gauge indicates 98 kPa (1

kgf/cm, 14 psi), close the high pressure hand valve.

(c)  Using a gas leak tester, check the system for leakage.
If leak is found, repair the faulty component or connection.

5. 

CHARGE EMPTY REFRIGERATION SYSTEM WITH
REFRIGERANT (LIQUID)
HINT: This step is used to charge an empty system through
the high pressure side with refrigerant in a liquid state.
NOTICE:

•

Never run the engine when charging the system
through the high pressure side with refrigerant in a
liquid stae.

•

Do not open the low pressure hand valve when the
system is being charged with liquid refrigerant.

(a)  Open the high pressure hand valve fully.
(b)  Charge the system with specified amount of refrigerant,

then close the high pressure hand valve.

HINT:

•

A fully charged system is indicated by the sight glass
being free of any bubbles.

•

If the low pressure gauge does not show a reading, the
system is clogged and must be repaired.

AC–18

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AIR CONDITIONING SYSTEM

Evacuation Air in Refrigeration 
System and Charging with Refrigerant

6.  CHARGE PARTIALLY REFRIGERATION SYSTEM WITH

REFRIGERANT (VAPOR)
HINT: This step is used to charge the system through the low
pressure side with refrigerant in a vapor state.
NOTICE: Do not open the high pressure hand valve when
running the engine.
(a)  Run the engine at ideling speed and operate the air

conditioner.

(b)  Open the low pressure hand valve.
NOTICE: Adjust the hand valve so that the low pressure
gauge does not indicate over limited pressure of charg-
ing cylinder.
(c)  Close the low pressure hand valve when the sight glass

is free of any bubbles and stop the engine.

NOTICE: Be careful not to overcharge the system with re-
frigerant as it may cause of troubles.

7.  REMOVE MANIFOLD GAUGE SET FROM SERVICE

VALVES
See page 

AC–15

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AIR CONDITIONING SYSTEM

Evacuation Air in Refrigeration 
System and Charging with Refrigerant

AC–19